/*
 * Synopsys DesignWare Multimedia Card Interface driver
 *  (Based on NXP driver for lpc 31xx)
 *
 * Copyright (C) 2009 NXP Semiconductors
 * Copyright (C) 2009, 2010 Imagination Technologies Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/blkdev.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/dw_mmc.h>
#include <linux/bitops.h>
#include <linux/regulator/consumer.h>
#include <linux/workqueue.h>
#include <linux/of.h>
#include <linux/of_gpio.h>

#include "dw_mmc.h"

/* Common flag combinations */
#define DW_MCI_DATA_ERROR_FLAGS (SDMMC_INT_DTO | SDMMC_INT_DCRC | \
                                 SDMMC_INT_HTO | SDMMC_INT_SBE  | \
                                 SDMMC_INT_EBE)
#define DW_MCI_CMD_ERROR_FLAGS  (SDMMC_INT_RTO | SDMMC_INT_RCRC | \
                                 SDMMC_INT_RESP_ERR)
#define DW_MCI_ERROR_FLAGS      (DW_MCI_DATA_ERROR_FLAGS | \
                                 DW_MCI_CMD_ERROR_FLAGS  | SDMMC_INT_HLE)
#define DW_MCI_SEND_STATUS      1
#define DW_MCI_RECV_STATUS      2
#define DW_MCI_DMA_THRESHOLD    16

#ifdef CONFIG_MMC_DW_IDMAC
struct idmac_desc {
        u32             des0;   /* Control Descriptor */
#define IDMAC_DES0_DIC  BIT(1)
#define IDMAC_DES0_LD   BIT(2)
#define IDMAC_DES0_FD   BIT(3)
#define IDMAC_DES0_CH   BIT(4)
#define IDMAC_DES0_ER   BIT(5)
#define IDMAC_DES0_CES  BIT(30)
#define IDMAC_DES0_OWN  BIT(31)

        u32             des1;   /* Buffer sizes */
#define IDMAC_SET_BUFFER1_SIZE(d, s) \
        ((d)->des1 = ((d)->des1 & 0x03ffe000) | ((s) & 0x1fff))

        u32             des2;   /* buffer 1 physical address */

        u32             des3;   /* buffer 2 physical address */
};
#endif /* CONFIG_MMC_DW_IDMAC */

/**
 * struct dw_mci_slot - MMC slot state
 * @mmc: The mmc_host representing this slot.
 * @host: The MMC controller this slot is using.
 * @quirks: Slot-level quirks (DW_MCI_SLOT_QUIRK_XXX)
 * @wp_gpio: If gpio_is_valid() we'll use this to read write protect.
 * @ctype: Card type for this slot.
 * @mrq: mmc_request currently being processed or waiting to be
 *      processed, or NULL when the slot is idle.
 * @queue_node: List node for placing this node in the @queue list of
 *      &struct dw_mci.
 * @clock: Clock rate configured by set_ios(). Protected by host->lock.
 * @flags: Random state bits associated with the slot.
 * @id: Number of this slot.
 * @last_detect_state: Most recently observed card detect state.
 */
struct dw_mci_slot {
        struct mmc_host         *mmc;
        struct dw_mci           *host;

        int                     quirks;
        int                     wp_gpio;

        u32                     ctype;

        struct mmc_request      *mrq;
        struct list_head        queue_node;

        unsigned int            clock;
        unsigned long           flags;
#define DW_MMC_CARD_PRESENT     0
#define DW_MMC_CARD_NEED_INIT   1
        int                     id;
        int                     last_detect_state;
};

#if defined(CONFIG_DEBUG_FS)
static int dw_mci_req_show(struct seq_file *s, void *v)
{
        struct dw_mci_slot *slot = s->private;
        struct mmc_request *mrq;
        struct mmc_command *cmd;
        struct mmc_command *stop;
        struct mmc_data *data;

        /* Make sure we get a consistent snapshot */
        spin_lock_bh(&slot->host->lock);
        mrq = slot->mrq;

        if (mrq) {
                cmd = mrq->cmd;
                data = mrq->data;
                stop = mrq->stop;

                if (cmd)
                        seq_printf(s,
                                   "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
                                   cmd->opcode, cmd->arg, cmd->flags,
                                   cmd->resp[0], cmd->resp[1], cmd->resp[2],
                                   cmd->resp[2], cmd->error);
                if (data)
                        seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
                                   data->bytes_xfered, data->blocks,
                                   data->blksz, data->flags, data->error);
                if (stop)
                        seq_printf(s,
                                   "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
                                   stop->opcode, stop->arg, stop->flags,
                                   stop->resp[0], stop->resp[1], stop->resp[2],
                                   stop->resp[2], stop->error);
        }

        spin_unlock_bh(&slot->host->lock);

        return 0;
}

static int dw_mci_req_open(struct inode *inode, struct file *file)
{
        return single_open(file, dw_mci_req_show, inode->i_private);
}

static const struct file_operations dw_mci_req_fops = {
        .owner          = THIS_MODULE,
        .open           = dw_mci_req_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int dw_mci_regs_show(struct seq_file *s, void *v)
{
        seq_printf(s, "STATUS:\t0x%08x\n", SDMMC_STATUS);
        seq_printf(s, "RINTSTS:\t0x%08x\n", SDMMC_RINTSTS);
        seq_printf(s, "CMD:\t0x%08x\n", SDMMC_CMD);
        seq_printf(s, "CTRL:\t0x%08x\n", SDMMC_CTRL);
        seq_printf(s, "INTMASK:\t0x%08x\n", SDMMC_INTMASK);
        seq_printf(s, "CLKENA:\t0x%08x\n", SDMMC_CLKENA);

        return 0;
}

static int dw_mci_regs_open(struct inode *inode, struct file *file)
{
        return single_open(file, dw_mci_regs_show, inode->i_private);
}

static const struct file_operations dw_mci_regs_fops = {
        .owner          = THIS_MODULE,
        .open           = dw_mci_regs_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static void dw_mci_init_debugfs(struct dw_mci_slot *slot)
{
        struct mmc_host *mmc = slot->mmc;
        struct dw_mci *host = slot->host;
        struct dentry *root;
        struct dentry *node;

        root = mmc->debugfs_root;
        if (!root)
                return;

        node = debugfs_create_file("regs", S_IRUSR, root, host,
                                   &dw_mci_regs_fops);
        if (!node)
                goto err;

        node = debugfs_create_file("req", S_IRUSR, root, slot,
                                   &dw_mci_req_fops);
        if (!node)
                goto err;

        node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
        if (!node)
                goto err;

        node = debugfs_create_x32("pending_events", S_IRUSR, root,
                                  (u32 *)&host->pending_events);
        if (!node)
                goto err;

        node = debugfs_create_x32("completed_events", S_IRUSR, root,
                                  (u32 *)&host->completed_events);
        if (!node)
                goto err;

        return;

err:
        dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
}
#endif /* defined(CONFIG_DEBUG_FS) */

static void dw_mci_set_timeout(struct dw_mci *host)
{
        /* timeout (maximum) */
        mci_writel(host, TMOUT, 0xffffffff);
}

static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd)
{
        struct mmc_data *data;
        struct dw_mci_slot *slot = mmc_priv(mmc);
        const struct dw_mci_drv_data *drv_data = slot->host->drv_data;
        u32 cmdr;
        cmd->error = -EINPROGRESS;

        cmdr = cmd->opcode;

        if (cmdr == MMC_STOP_TRANSMISSION)
                cmdr |= SDMMC_CMD_STOP;
        else
                cmdr |= SDMMC_CMD_PRV_DAT_WAIT;

        if (cmd->flags & MMC_RSP_PRESENT) {
                /* We expect a response, so set this bit */
                cmdr |= SDMMC_CMD_RESP_EXP;
                if (cmd->flags & MMC_RSP_136)
                        cmdr |= SDMMC_CMD_RESP_LONG;
        }

        if (cmd->flags & MMC_RSP_CRC)
                cmdr |= SDMMC_CMD_RESP_CRC;

        data = cmd->data;
        if (data) {
                cmdr |= SDMMC_CMD_DAT_EXP;
                if (data->flags & MMC_DATA_STREAM)
                        cmdr |= SDMMC_CMD_STRM_MODE;
                if (data->flags & MMC_DATA_WRITE)
                        cmdr |= SDMMC_CMD_DAT_WR;
        }

        if (drv_data && drv_data->prepare_command)
                drv_data->prepare_command(slot->host, &cmdr);

        return cmdr;
}

static void dw_mci_start_command(struct dw_mci *host,
                                 struct mmc_command *cmd, u32 cmd_flags)
{
        host->cmd = cmd;
        dev_vdbg(host->dev,
                 "start command: ARGR=0x%08x CMDR=0x%08x\n",
                 cmd->arg, cmd_flags);

        mci_writel(host, CMDARG, cmd->arg);
        wmb();

        mci_writel(host, CMD, cmd_flags | SDMMC_CMD_START);
}

static void send_stop_cmd(struct dw_mci *host, struct mmc_data *data)
{
        dw_mci_start_command(host, data->stop, host->stop_cmdr);
}

/* DMA interface functions */
static void dw_mci_stop_dma(struct dw_mci *host)
{
        if (host->using_dma) {
                host->dma_ops->stop(host);
                host->dma_ops->cleanup(host);
        } else {
                /* Data transfer was stopped by the interrupt handler */
                set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
        }
}

static int dw_mci_get_dma_dir(struct mmc_data *data)
{
        if (data->flags & MMC_DATA_WRITE)
                return DMA_TO_DEVICE;
        else
                return DMA_FROM_DEVICE;
}

#ifdef CONFIG_MMC_DW_IDMAC
static void dw_mci_dma_cleanup(struct dw_mci *host)
{
        struct mmc_data *data = host->data;

        if (data)
                if (!data->host_cookie)
                        dma_unmap_sg(host->dev,
                                     data->sg,
                                     data->sg_len,
                                     dw_mci_get_dma_dir(data));
}

static void dw_mci_idmac_stop_dma(struct dw_mci *host)
{
        u32 temp;

        /* Disable and reset the IDMAC interface */
        temp = mci_readl(host, CTRL);
        temp &= ~SDMMC_CTRL_USE_IDMAC;
        temp |= SDMMC_CTRL_DMA_RESET;
        mci_writel(host, CTRL, temp);

        /* Stop the IDMAC running */
        temp = mci_readl(host, BMOD);
        temp &= ~(SDMMC_IDMAC_ENABLE | SDMMC_IDMAC_FB);
        mci_writel(host, BMOD, temp);
}

static void dw_mci_idmac_complete_dma(struct dw_mci *host)
{
        struct mmc_data *data = host->data;

        dev_vdbg(host->dev, "DMA complete\n");

        host->dma_ops->cleanup(host);

        /*
         * If the card was removed, data will be NULL. No point in trying to
         * send the stop command or waiting for NBUSY in this case.
         */
        if (data) {
                set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
                tasklet_schedule(&host->tasklet);
        }
}

static void dw_mci_translate_sglist(struct dw_mci *host, struct mmc_data *data,
                                    unsigned int sg_len)
{
        int i;
        struct idmac_desc *desc = host->sg_cpu;

        for (i = 0; i < sg_len; i++, desc++) {
                unsigned int length = sg_dma_len(&data->sg[i]);
                u32 mem_addr = sg_dma_address(&data->sg[i]);

                /* Set the OWN bit and disable interrupts for this descriptor */
                desc->des0 = IDMAC_DES0_OWN | IDMAC_DES0_DIC | IDMAC_DES0_CH;

                /* Buffer length */
                IDMAC_SET_BUFFER1_SIZE(desc, length);

                /* Physical address to DMA to/from */
                desc->des2 = mem_addr;
        }

        /* Set first descriptor */
        desc = host->sg_cpu;
        desc->des0 |= IDMAC_DES0_FD;

        /* Set last descriptor */
        desc = host->sg_cpu + (i - 1) * sizeof(struct idmac_desc);
        desc->des0 &= ~(IDMAC_DES0_CH | IDMAC_DES0_DIC);
        desc->des0 |= IDMAC_DES0_LD;

        wmb();
}

static void dw_mci_idmac_start_dma(struct dw_mci *host, unsigned int sg_len)
{
        u32 temp;

        dw_mci_translate_sglist(host, host->data, sg_len);

        /* Select IDMAC interface */
        temp = mci_readl(host, CTRL);
        temp |= SDMMC_CTRL_USE_IDMAC;
        mci_writel(host, CTRL, temp);

        wmb();

        /* Enable the IDMAC */
        temp = mci_readl(host, BMOD);
        temp |= SDMMC_IDMAC_ENABLE | SDMMC_IDMAC_FB;
        mci_writel(host, BMOD, temp);

        /* Start it running */
        mci_writel(host, PLDMND, 1);
}

static int dw_mci_idmac_init(struct dw_mci *host)
{
        struct idmac_desc *p;
        int i;

        /* Number of descriptors in the ring buffer */
        host->ring_size = PAGE_SIZE / sizeof(struct idmac_desc);

        /* Forward link the descriptor list */
        for (i = 0, p = host->sg_cpu; i < host->ring_size - 1; i++, p++)
                p->des3 = host->sg_dma + (sizeof(struct idmac_desc) * (i + 1));

        /* Set the last descriptor as the end-of-ring descriptor */
        p->des3 = host->sg_dma;
        p->des0 = IDMAC_DES0_ER;

        mci_writel(host, BMOD, SDMMC_IDMAC_SWRESET);

        /* Mask out interrupts - get Tx & Rx complete only */
        mci_writel(host, IDINTEN, SDMMC_IDMAC_INT_NI | SDMMC_IDMAC_INT_RI |
                   SDMMC_IDMAC_INT_TI);

        /* Set the descriptor base address */
        mci_writel(host, DBADDR, host->sg_dma);
        return 0;
}

static const struct dw_mci_dma_ops dw_mci_idmac_ops = {
        .init = dw_mci_idmac_init,
        .start = dw_mci_idmac_start_dma,
        .stop = dw_mci_idmac_stop_dma,
        .complete = dw_mci_idmac_complete_dma,
        .cleanup = dw_mci_dma_cleanup,
};
#endif /* CONFIG_MMC_DW_IDMAC */

static int dw_mci_pre_dma_transfer(struct dw_mci *host,
                                   struct mmc_data *data,
                                   bool next)
{
        struct scatterlist *sg;
        unsigned int i, sg_len;

        if (!next && data->host_cookie)
                return data->host_cookie;

        /*
         * We don't do DMA on "complex" transfers, i.e. with
         * non-word-aligned buffers or lengths. Also, we don't bother
         * with all the DMA setup overhead for short transfers.
         */
        if (data->blocks * data->blksz < DW_MCI_DMA_THRESHOLD)
                return -EINVAL;

        if (data->blksz & 3)
                return -EINVAL;

        for_each_sg(data->sg, sg, data->sg_len, i) {
                if (sg->offset & 3 || sg->length & 3)
                        return -EINVAL;
        }

        sg_len = dma_map_sg(host->dev,
                            data->sg,
                            data->sg_len,
                            dw_mci_get_dma_dir(data));
        if (sg_len == 0)
                return -EINVAL;

        if (next)
                data->host_cookie = sg_len;

        return sg_len;
}

static void dw_mci_pre_req(struct mmc_host *mmc,
                           struct mmc_request *mrq,
                           bool is_first_req)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct mmc_data *data = mrq->data;

        if (!slot->host->use_dma || !data)
                return;

        if (data->host_cookie) {
                data->host_cookie = 0;
                return;
        }

        if (dw_mci_pre_dma_transfer(slot->host, mrq->data, 1) < 0)
                data->host_cookie = 0;
}

static void dw_mci_post_req(struct mmc_host *mmc,
                            struct mmc_request *mrq,
                            int err)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct mmc_data *data = mrq->data;

        if (!slot->host->use_dma || !data)
                return;

        if (data->host_cookie)
                dma_unmap_sg(slot->host->dev,
                             data->sg,
                             data->sg_len,
                             dw_mci_get_dma_dir(data));
        data->host_cookie = 0;
}

static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
{
        int sg_len;
        u32 temp;

        host->using_dma = 0;

        /* If we don't have a channel, we can't do DMA */
        if (!host->use_dma)
                return -ENODEV;

        sg_len = dw_mci_pre_dma_transfer(host, data, 0);
        if (sg_len < 0) {
                host->dma_ops->stop(host);
                return sg_len;
        }

        host->using_dma = 1;

        dev_vdbg(host->dev,
                 "sd sg_cpu: %#lx sg_dma: %#lx sg_len: %d\n",
                 (unsigned long)host->sg_cpu, (unsigned long)host->sg_dma,
                 sg_len);

        /* Enable the DMA interface */
        temp = mci_readl(host, CTRL);
        temp |= SDMMC_CTRL_DMA_ENABLE;
        mci_writel(host, CTRL, temp);

        /* Disable RX/TX IRQs, let DMA handle it */
        temp = mci_readl(host, INTMASK);
        temp  &= ~(SDMMC_INT_RXDR | SDMMC_INT_TXDR);
        mci_writel(host, INTMASK, temp);

        host->dma_ops->start(host, sg_len);

        return 0;
}

static void dw_mci_submit_data(struct dw_mci *host, struct mmc_data *data)
{
        u32 temp;

        data->error = -EINPROGRESS;

        WARN_ON(host->data);
        host->sg = NULL;
        host->data = data;

        if (data->flags & MMC_DATA_READ)
                host->dir_status = DW_MCI_RECV_STATUS;
        else
                host->dir_status = DW_MCI_SEND_STATUS;

        if (dw_mci_submit_data_dma(host, data)) {
                int flags = SG_MITER_ATOMIC;
                if (host->data->flags & MMC_DATA_READ)
                        flags |= SG_MITER_TO_SG;
                else
                        flags |= SG_MITER_FROM_SG;

                sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
                host->sg = data->sg;
                host->part_buf_start = 0;
                host->part_buf_count = 0;

                mci_writel(host, RINTSTS, SDMMC_INT_TXDR | SDMMC_INT_RXDR);
                temp = mci_readl(host, INTMASK);
                temp |= SDMMC_INT_TXDR | SDMMC_INT_RXDR;
                mci_writel(host, INTMASK, temp);

                temp = mci_readl(host, CTRL);
                temp &= ~SDMMC_CTRL_DMA_ENABLE;
                mci_writel(host, CTRL, temp);
        }
}

static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
{
        struct dw_mci *host = slot->host;
        unsigned long timeout = jiffies + msecs_to_jiffies(500);
        unsigned int cmd_status = 0;

        mci_writel(host, CMDARG, arg);
        wmb();
        mci_writel(host, CMD, SDMMC_CMD_START | cmd);

        while (time_before(jiffies, timeout)) {
                cmd_status = mci_readl(host, CMD);
                if (!(cmd_status & SDMMC_CMD_START))
                        return;
        }
        dev_err(&slot->mmc->class_dev,
                "Timeout sending command (cmd %#x arg %#x status %#x)\n",
                cmd, arg, cmd_status);
}

static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
{
        struct dw_mci *host = slot->host;
        u32 div;
        u32 clk_en_a;

        if (slot->clock != host->current_speed || force_clkinit) {
                div = host->bus_hz / slot->clock;
                if (host->bus_hz % slot->clock && host->bus_hz > slot->clock)
                        /*
                         * move the + 1 after the divide to prevent
                         * over-clocking the card.
                         */
                        div += 1;

                div = (host->bus_hz != slot->clock) ? DIV_ROUND_UP(div, 2) : 0;

                dev_info(&slot->mmc->class_dev,
                         "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ"
                         " div = %d)\n", slot->id, host->bus_hz, slot->clock,
                         div ? ((host->bus_hz / div) >> 1) : host->bus_hz, div);

                /* disable clock */
                mci_writel(host, CLKENA, 0);
                mci_writel(host, CLKSRC, 0);

                /* inform CIU */
                mci_send_cmd(slot,
                             SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);

                /* set clock to desired speed */
                mci_writel(host, CLKDIV, div);

                /* inform CIU */
                mci_send_cmd(slot,
                             SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);

                /* enable clock; only low power if no SDIO */
                clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
                if (!(mci_readl(host, INTMASK) & SDMMC_INT_SDIO(slot->id)))
                        clk_en_a |= SDMMC_CLKEN_LOW_PWR << slot->id;
                mci_writel(host, CLKENA, clk_en_a);

                /* inform CIU */
                mci_send_cmd(slot,
                             SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);

                host->current_speed = slot->clock;
        }

        /* Set the current slot bus width */
        mci_writel(host, CTYPE, (slot->ctype << slot->id));
}

static void __dw_mci_start_request(struct dw_mci *host,
                                   struct dw_mci_slot *slot,
                                   struct mmc_command *cmd)
{
        struct mmc_request *mrq;
        struct mmc_data *data;
        u32 cmdflags;

        mrq = slot->mrq;
        if (host->pdata->select_slot)
                host->pdata->select_slot(slot->id);

        host->cur_slot = slot;
        host->mrq = mrq;

        host->pending_events = 0;
        host->completed_events = 0;
        host->data_status = 0;

        data = cmd->data;
        if (data) {
                dw_mci_set_timeout(host);
                mci_writel(host, BYTCNT, data->blksz*data->blocks);
                mci_writel(host, BLKSIZ, data->blksz);
        }

        cmdflags = dw_mci_prepare_command(slot->mmc, cmd);

        /* this is the first command, send the initialization clock */
        if (test_and_clear_bit(DW_MMC_CARD_NEED_INIT, &slot->flags))
                cmdflags |= SDMMC_CMD_INIT;

        if (data) {
                dw_mci_submit_data(host, data);
                wmb();
        }

        dw_mci_start_command(host, cmd, cmdflags);

        if (mrq->stop)
                host->stop_cmdr = dw_mci_prepare_command(slot->mmc, mrq->stop);
}

static void dw_mci_start_request(struct dw_mci *host,
                                 struct dw_mci_slot *slot)
{
        struct mmc_request *mrq = slot->mrq;
        struct mmc_command *cmd;

        cmd = mrq->sbc ? mrq->sbc : mrq->cmd;
        __dw_mci_start_request(host, slot, cmd);
}

/* must be called with host->lock held */
static void dw_mci_queue_request(struct dw_mci *host, struct dw_mci_slot *slot,
                                 struct mmc_request *mrq)
{
        dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n",
                 host->state);

        slot->mrq = mrq;

        if (host->state == STATE_IDLE) {
                host->state = STATE_SENDING_CMD;
                dw_mci_start_request(host, slot);
        } else {
                list_add_tail(&slot->queue_node, &host->queue);
        }
}

static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;

        WARN_ON(slot->mrq);

        /*
         * The check for card presence and queueing of the request must be
         * atomic, otherwise the card could be removed in between and the
         * request wouldn't fail until another card was inserted.
         */
        spin_lock_bh(&host->lock);

        if (!test_bit(DW_MMC_CARD_PRESENT, &slot->flags)) {
                spin_unlock_bh(&host->lock);
                mrq->cmd->error = -ENOMEDIUM;
                mmc_request_done(mmc, mrq);
                return;
        }

        dw_mci_queue_request(host, slot, mrq);

        spin_unlock_bh(&host->lock);
}

static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        const struct dw_mci_drv_data *drv_data = slot->host->drv_data;
        u32 regs;

        switch (ios->bus_width) {
        case MMC_BUS_WIDTH_4:
                slot->ctype = SDMMC_CTYPE_4BIT;
                break;
        case MMC_BUS_WIDTH_8:
                slot->ctype = SDMMC_CTYPE_8BIT;
                break;
        default:
                /* set default 1 bit mode */
                slot->ctype = SDMMC_CTYPE_1BIT;
        }

        regs = mci_readl(slot->host, UHS_REG);

        /* DDR mode set */
        if (ios->timing == MMC_TIMING_UHS_DDR50)
                regs |= (0x1 << slot->id) << 16;
        else
                regs &= ~(0x1 << slot->id) << 16;

        mci_writel(slot->host, UHS_REG, regs);

        if (ios->clock) {
                /*
                 * Use mirror of ios->clock to prevent race with mmc
                 * core ios update when finding the minimum.
                 */
                slot->clock = ios->clock;
        }

        if (drv_data && drv_data->set_ios)
                drv_data->set_ios(slot->host, ios);

        /* Slot specific timing and width adjustment */
        dw_mci_setup_bus(slot, false);

        switch (ios->power_mode) {
        case MMC_POWER_UP:
                set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
                break;
        default:
                break;
        }
}

static int dw_mci_get_ro(struct mmc_host *mmc)
{
        int read_only;
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci_board *brd = slot->host->pdata;

        /* Use platform get_ro function, else try on board write protect */
        if (slot->quirks & DW_MCI_SLOT_QUIRK_NO_WRITE_PROTECT)
                read_only = 0;
        else if (brd->get_ro)
                read_only = brd->get_ro(slot->id);
        else if (gpio_is_valid(slot->wp_gpio))
                read_only = gpio_get_value(slot->wp_gpio);
        else
                read_only =
                        mci_readl(slot->host, WRTPRT) & (1 << slot->id) ? 1 : 0;

        dev_dbg(&mmc->class_dev, "card is %s\n",
                read_only ? "read-only" : "read-write");

        return read_only;
}

static int dw_mci_get_cd(struct mmc_host *mmc)
{
        int present;
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci_board *brd = slot->host->pdata;

        /* Use platform get_cd function, else try onboard card detect */
        if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
                present = 1;
        else if (brd->get_cd)
                present = !brd->get_cd(slot->id);
        else
                present = (mci_readl(slot->host, CDETECT) & (1 << slot->id))
                        == 0 ? 1 : 0;

        if (present)
                dev_dbg(&mmc->class_dev, "card is present\n");
        else
                dev_dbg(&mmc->class_dev, "card is not present\n");

        return present;
}

/*
 * Disable lower power mode.
 *
 * Low power mode will stop the card clock when idle.  According to the
 * description of the CLKENA register we should disable low power mode
 * for SDIO cards if we need SDIO interrupts to work.
 *
 * This function is fast if low power mode is already disabled.
 */
static void dw_mci_disable_low_power(struct dw_mci_slot *slot)
{
        struct dw_mci *host = slot->host;
        u32 clk_en_a;
        const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id;

        clk_en_a = mci_readl(host, CLKENA);

        if (clk_en_a & clken_low_pwr) {
                mci_writel(host, CLKENA, clk_en_a & ~clken_low_pwr);
                mci_send_cmd(slot, SDMMC_CMD_UPD_CLK |
                             SDMMC_CMD_PRV_DAT_WAIT, 0);
        }
}

static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;
        u32 int_mask;

        /* Enable/disable Slot Specific SDIO interrupt */
        int_mask = mci_readl(host, INTMASK);
        if (enb) {
                /*
                 * Turn off low power mode if it was enabled.  This is a bit of
                 * a heavy operation and we disable / enable IRQs a lot, so
                 * we'll leave low power mode disabled and it will get
                 * re-enabled again in dw_mci_setup_bus().
                 */
                dw_mci_disable_low_power(slot);

                mci_writel(host, INTMASK,
                           (int_mask | SDMMC_INT_SDIO(slot->id)));
        } else {
                mci_writel(host, INTMASK,
                           (int_mask & ~SDMMC_INT_SDIO(slot->id)));
        }
}

static const struct mmc_host_ops dw_mci_ops = {
        .request                = dw_mci_request,
        .pre_req                = dw_mci_pre_req,
        .post_req               = dw_mci_post_req,
        .set_ios                = dw_mci_set_ios,
        .get_ro                 = dw_mci_get_ro,
        .get_cd                 = dw_mci_get_cd,
        .enable_sdio_irq        = dw_mci_enable_sdio_irq,
};

static void dw_mci_request_end(struct dw_mci *host, struct mmc_request *mrq)
        __releases(&host->lock)
        __acquires(&host->lock)
{
        struct dw_mci_slot *slot;
        struct mmc_host *prev_mmc = host->cur_slot->mmc;

        WARN_ON(host->cmd || host->data);

        host->cur_slot->mrq = NULL;
        host->mrq = NULL;
        if (!list_empty(&host->queue)) {
                slot = list_entry(host->queue.next,
                                  struct dw_mci_slot, queue_node);
                list_del(&slot->queue_node);
                dev_vdbg(host->dev, "list not empty: %s is next\n",
                         mmc_hostname(slot->mmc));
                host->state = STATE_SENDING_CMD;
                dw_mci_start_request(host, slot);
        } else {
                dev_vdbg(host->dev, "list empty\n");
                host->state = STATE_IDLE;
        }

        spin_unlock(&host->lock);
        mmc_request_done(prev_mmc, mrq);
        spin_lock(&host->lock);
}

static void dw_mci_command_complete(struct dw_mci *host, struct mmc_command *cmd)
{
        u32 status = host->cmd_status;

        host->cmd_status = 0;

        /* Read the response from the card (up to 16 bytes) */
        if (cmd->flags & MMC_RSP_PRESENT) {
                if (cmd->flags & MMC_RSP_136) {
                        cmd->resp[3] = mci_readl(host, RESP0);
                        cmd->resp[2] = mci_readl(host, RESP1);
                        cmd->resp[1] = mci_readl(host, RESP2);
                        cmd->resp[0] = mci_readl(host, RESP3);
                } else {
                        cmd->resp[0] = mci_readl(host, RESP0);
                        cmd->resp[1] = 0;
                        cmd->resp[2] = 0;
                        cmd->resp[3] = 0;
                }
        }

        if (status & SDMMC_INT_RTO)
                cmd->error = -ETIMEDOUT;
        else if ((cmd->flags & MMC_RSP_CRC) && (status & SDMMC_INT_RCRC))
                cmd->error = -EILSEQ;
        else if (status & SDMMC_INT_RESP_ERR)
                cmd->error = -EIO;
        else
                cmd->error = 0;

        if (cmd->error) {
                /* newer ip versions need a delay between retries */
                if (host->quirks & DW_MCI_QUIRK_RETRY_DELAY)
                        mdelay(20);

                if (cmd->data) {
                        dw_mci_stop_dma(host);
                        host->data = NULL;
                }
        }

}

static void dw_mci_tasklet_func(unsigned long priv)
{
        struct dw_mci *host = (struct dw_mci *)priv;
        struct mmc_data *data;
        struct mmc_command *cmd;
        enum dw_mci_state state;
        enum dw_mci_state prev_state;
        u32 status, ctrl;

        spin_lock(&host->lock);

        state = host->state;
        data = host->data;

        do {
                prev_state = state;

                switch (state) {
                case STATE_IDLE:
                        break;

                case STATE_SENDING_CMD:
                        if (!test_and_clear_bit(EVENT_CMD_COMPLETE,
                                                &host->pending_events))
                                break;

                        cmd = host->cmd;
                        host->cmd = NULL;
                        set_bit(EVENT_CMD_COMPLETE, &host->completed_events);
                        dw_mci_command_complete(host, cmd);
                        if (cmd == host->mrq->sbc && !cmd->error) {
                                prev_state = state = STATE_SENDING_CMD;
                                __dw_mci_start_request(host, host->cur_slot,
                                                       host->mrq->cmd);
                                goto unlock;
                        }

                        if (!host->mrq->data || cmd->error) {
                                dw_mci_request_end(host, host->mrq);
                                goto unlock;
                        }

                        prev_state = state = STATE_SENDING_DATA;
                        /* fall through */

                case STATE_SENDING_DATA:
                        if (test_and_clear_bit(EVENT_DATA_ERROR,
                                               &host->pending_events)) {
                                dw_mci_stop_dma(host);
                                if (data->stop)
                                        send_stop_cmd(host, data);
                                state = STATE_DATA_ERROR;
                                break;
                        }

                        if (!test_and_clear_bit(EVENT_XFER_COMPLETE,
                                                &host->pending_events))
                                break;

                        set_bit(EVENT_XFER_COMPLETE, &host->completed_events);
                        prev_state = state = STATE_DATA_BUSY;
                        /* fall through */

                case STATE_DATA_BUSY:
                        if (!test_and_clear_bit(EVENT_DATA_COMPLETE,
                                                &host->pending_events))
                                break;

                        host->data = NULL;
                        set_bit(EVENT_DATA_COMPLETE, &host->completed_events);
                        status = host->data_status;

                        if (status & DW_MCI_DATA_ERROR_FLAGS) {
                                if (status & SDMMC_INT_DTO) {
                                        data->error = -ETIMEDOUT;
                                } else if (status & SDMMC_INT_DCRC) {
                                        data->error = -EILSEQ;
                                } else if (status & SDMMC_INT_EBE &&
                                           host->dir_status ==
                                                        DW_MCI_SEND_STATUS) {
                                        /*
                                         * No data CRC status was returned.
                                         * The number of bytes transferred will
                                         * be exaggerated in PIO mode.
                                         */
                                        data->bytes_xfered = 0;
                                        data->error = -ETIMEDOUT;
                                } else {
                                        dev_err(host->dev,
                                                "data FIFO error "
                                                "(status=%08x)\n",
                                                status);
                                        data->error = -EIO;
                                }
                                /*
                                 * After an error, there may be data lingering
                                 * in the FIFO, so reset it - doing so
                                 * generates a block interrupt, hence setting
                                 * the scatter-gather pointer to NULL.
                                 */
                                sg_miter_stop(&host->sg_miter);
                                host->sg = NULL;
                                ctrl = mci_readl(host, CTRL);
                                ctrl |= SDMMC_CTRL_FIFO_RESET;
                                mci_writel(host, CTRL, ctrl);
                        } else {
                                data->bytes_xfered = data->blocks * data->blksz;
                                data->error = 0;
                        }

                        if (!data->stop) {
                                dw_mci_request_end(host, host->mrq);
                                goto unlock;
                        }

                        if (host->mrq->sbc && !data->error) {
                                data->stop->error = 0;
                                dw_mci_request_end(host, host->mrq);
                                goto unlock;
                        }

                        prev_state = state = STATE_SENDING_STOP;
                        if (!data->error)
                                send_stop_cmd(host, data);
                        /* fall through */

                case STATE_SENDING_STOP:
                        if (!test_and_clear_bit(EVENT_CMD_COMPLETE,
                                                &host->pending_events))
                                break;

                        host->cmd = NULL;
                        dw_mci_command_complete(host, host->mrq->stop);
                        dw_mci_request_end(host, host->mrq);
                        goto unlock;

                case STATE_DATA_ERROR:
                        if (!test_and_clear_bit(EVENT_XFER_COMPLETE,
                                                &host->pending_events))
                                break;

                        state = STATE_DATA_BUSY;
                        break;
                }
        } while (state != prev_state);

        host->state = state;
unlock:
        spin_unlock(&host->lock);

}

/* push final bytes to part_buf, only use during push */
static void dw_mci_set_part_bytes(struct dw_mci *host, void *buf, int cnt)
{
        memcpy((void *)&host->part_buf, buf, cnt);
        host->part_buf_count = cnt;
}

/* append bytes to part_buf, only use during push */
static int dw_mci_push_part_bytes(struct dw_mci *host, void *buf, int cnt)
{
        cnt = min(cnt, (1 << host->data_shift) - host->part_buf_count);
        memcpy((void *)&host->part_buf + host->part_buf_count, buf, cnt);
        host->part_buf_count += cnt;
        return cnt;
}

/* pull first bytes from part_buf, only use during pull */
static int dw_mci_pull_part_bytes(struct dw_mci *host, void *buf, int cnt)
{
        cnt = min(cnt, (int)host->part_buf_count);
        if (cnt) {
                memcpy(buf, (void *)&host->part_buf + host->part_buf_start,
                       cnt);
                host->part_buf_count -= cnt;
                host->part_buf_start += cnt;
        }
        return cnt;
}

/* pull final bytes from the part_buf, assuming it's just been filled */
static void dw_mci_pull_final_bytes(struct dw_mci *host, void *buf, int cnt)
{
        memcpy(buf, &host->part_buf, cnt);
        host->part_buf_start = cnt;
        host->part_buf_count = (1 << host->data_shift) - cnt;
}

static void dw_mci_push_data16(struct dw_mci *host, void *buf, int cnt)
{
        /* try and push anything in the part_buf */
        if (unlikely(host->part_buf_count)) {
                int len = dw_mci_push_part_bytes(host, buf, cnt);
                buf += len;
                cnt -= len;
                if (!sg_next(host->sg) || host->part_buf_count == 2) {
                        mci_writew(host, DATA(host->data_offset),
                                        host->part_buf16);
                        host->part_buf_count = 0;
                }
        }
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x1)) {
                while (cnt >= 2) {
                        u16 aligned_buf[64];
                        int len = min(cnt & -2, (int)sizeof(aligned_buf));
                        int items = len >> 1;
                        int i;
                        /* memcpy from input buffer into aligned buffer */
                        memcpy(aligned_buf, buf, len);
                        buf += len;
                        cnt -= len;
                        /* push data from aligned buffer into fifo */
                        for (i = 0; i < items; ++i)
                                mci_writew(host, DATA(host->data_offset),
                                                aligned_buf[i]);
                }
        } else
#endif
        {
                u16 *pdata = buf;
                for (; cnt >= 2; cnt -= 2)
                        mci_writew(host, DATA(host->data_offset), *pdata++);
                buf = pdata;
        }
        /* put anything remaining in the part_buf */
        if (cnt) {
                dw_mci_set_part_bytes(host, buf, cnt);
                if (!sg_next(host->sg))
                        mci_writew(host, DATA(host->data_offset),
                                        host->part_buf16);
        }
}

static void dw_mci_pull_data16(struct dw_mci *host, void *buf, int cnt)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x1)) {
                while (cnt >= 2) {
                        /* pull data from fifo into aligned buffer */
                        u16 aligned_buf[64];
                        int len = min(cnt & -2, (int)sizeof(aligned_buf));
                        int items = len >> 1;
                        int i;
                        for (i = 0; i < items; ++i)
                                aligned_buf[i] = mci_readw(host,
                                                DATA(host->data_offset));
                        /* memcpy from aligned buffer into output buffer */
                        memcpy(buf, aligned_buf, len);
                        buf += len;
                        cnt -= len;
                }
        } else
#endif
        {
                u16 *pdata = buf;
                for (; cnt >= 2; cnt -= 2)
                        *pdata++ = mci_readw(host, DATA(host->data_offset));
                buf = pdata;
        }
        if (cnt) {
                host->part_buf16 = mci_readw(host, DATA(host->data_offset));
                dw_mci_pull_final_bytes(host, buf, cnt);
        }
}

static void dw_mci_push_data32(struct dw_mci *host, void *buf, int cnt)
{
        /* try and push anything in the part_buf */
        if (unlikely(host->part_buf_count)) {
                int len = dw_mci_push_part_bytes(host, buf, cnt);
                buf += len;
                cnt -= len;
                if (!sg_next(host->sg) || host->part_buf_count == 4) {
                        mci_writel(host, DATA(host->data_offset),
                                        host->part_buf32);
                        host->part_buf_count = 0;
                }
        }
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x3)) {
                while (cnt >= 4) {
                        u32 aligned_buf[32];
                        int len = min(cnt & -4, (int)sizeof(aligned_buf));
                        int items = len >> 2;
                        int i;
                        /* memcpy from input buffer into aligned buffer */
                        memcpy(aligned_buf, buf, len);
                        buf += len;
                        cnt -= len;
                        /* push data from aligned buffer into fifo */
                        for (i = 0; i < items; ++i)
                                mci_writel(host, DATA(host->data_offset),
                                                aligned_buf[i]);
                }
        } else
#endif
        {
                u32 *pdata = buf;
                for (; cnt >= 4; cnt -= 4)
                        mci_writel(host, DATA(host->data_offset), *pdata++);
                buf = pdata;
        }
        /* put anything remaining in the part_buf */
        if (cnt) {
                dw_mci_set_part_bytes(host, buf, cnt);
                if (!sg_next(host->sg))
                        mci_writel(host, DATA(host->data_offset),
                                                host->part_buf32);
        }
}

static void dw_mci_pull_data32(struct dw_mci *host, void *buf, int cnt)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x3)) {
                while (cnt >= 4) {
                        /* pull data from fifo into aligned buffer */
                        u32 aligned_buf[32];
                        int len = min(cnt & -4, (int)sizeof(aligned_buf));
                        int items = len >> 2;
                        int i;
                        for (i = 0; i < items; ++i)
                                aligned_buf[i] = mci_readl(host,
                                                DATA(host->data_offset));
                        /* memcpy from aligned buffer into output buffer */
                        memcpy(buf, aligned_buf, len);
                        buf += len;
                        cnt -= len;
                }
        } else
#endif
        {
                u32 *pdata = buf;
                for (; cnt >= 4; cnt -= 4)
                        *pdata++ = mci_readl(host, DATA(host->data_offset));
                buf = pdata;
        }
        if (cnt) {
                host->part_buf32 = mci_readl(host, DATA(host->data_offset));
                dw_mci_pull_final_bytes(host, buf, cnt);
        }
}

static void dw_mci_push_data64(struct dw_mci *host, void *buf, int cnt)
{
        /* try and push anything in the part_buf */
        if (unlikely(host->part_buf_count)) {
                int len = dw_mci_push_part_bytes(host, buf, cnt);
                buf += len;
                cnt -= len;
                if (!sg_next(host->sg) || host->part_buf_count == 8) {
                        mci_writew(host, DATA(host->data_offset),
                                        host->part_buf);
                        host->part_buf_count = 0;
                }
        }
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x7)) {
                while (cnt >= 8) {
                        u64 aligned_buf[16];
                        int len = min(cnt & -8, (int)sizeof(aligned_buf));
                        int items = len >> 3;
                        int i;
                        /* memcpy from input buffer into aligned buffer */
                        memcpy(aligned_buf, buf, len);
                        buf += len;
                        cnt -= len;
                        /* push data from aligned buffer into fifo */
                        for (i = 0; i < items; ++i)
                                mci_writeq(host, DATA(host->data_offset),
                                                aligned_buf[i]);
                }
        } else
#endif
        {
                u64 *pdata = buf;
                for (; cnt >= 8; cnt -= 8)
                        mci_writeq(host, DATA(host->data_offset), *pdata++);
                buf = pdata;
        }
        /* put anything remaining in the part_buf */
        if (cnt) {
                dw_mci_set_part_bytes(host, buf, cnt);
                if (!sg_next(host->sg))
                        mci_writeq(host, DATA(host->data_offset),
                                        host->part_buf);
        }
}

static void dw_mci_pull_data64(struct dw_mci *host, void *buf, int cnt)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x7)) {
                while (cnt >= 8) {
                        /* pull data from fifo into aligned buffer */
                        u64 aligned_buf[16];
                        int len = min(cnt & -8, (int)sizeof(aligned_buf));
                        int items = len >> 3;
                        int i;
                        for (i = 0; i < items; ++i)
                                aligned_buf[i] = mci_readq(host,
                                                DATA(host->data_offset));
                        /* memcpy from aligned buffer into output buffer */
                        memcpy(buf, aligned_buf, len);
                        buf += len;
                        cnt -= len;
                }
        } else
#endif
        {
                u64 *pdata = buf;
                for (; cnt >= 8; cnt -= 8)
                        *pdata++ = mci_readq(host, DATA(host->data_offset));
                buf = pdata;
        }
        if (cnt) {
                host->part_buf = mci_readq(host, DATA(host->data_offset));
                dw_mci_pull_final_bytes(host, buf, cnt);
        }
}

static void dw_mci_pull_data(struct dw_mci *host, void *buf, int cnt)
{
        int len;

        /* get remaining partial bytes */
        len = dw_mci_pull_part_bytes(host, buf, cnt);
        if (unlikely(len == cnt))
                return;
        buf += len;
        cnt -= len;

        /* get the rest of the data */
        host->pull_data(host, buf, cnt);
}

static void dw_mci_read_data_pio(struct dw_mci *host)
{
        struct sg_mapping_iter *sg_miter = &host->sg_miter;
        void *buf;
        unsigned int offset;
        struct mmc_data *data = host->data;
        int shift = host->data_shift;
        u32 status;
        unsigned int nbytes = 0, len;
        unsigned int remain, fcnt;

        do {
                if (!sg_miter_next(sg_miter))
                        goto done;

                host->sg = sg_miter->piter.sg;
                buf = sg_miter->addr;
                remain = sg_miter->length;
                offset = 0;

                do {
                        fcnt = (SDMMC_GET_FCNT(mci_readl(host, STATUS))
                                        << shift) + host->part_buf_count;
                        len = min(remain, fcnt);
                        if (!len)
                                break;
                        dw_mci_pull_data(host, (void *)(buf + offset), len);
                        offset += len;
                        nbytes += len;
                        remain -= len;
                } while (remain);

                sg_miter->consumed = offset;
                status = mci_readl(host, MINTSTS);
                mci_writel(host, RINTSTS, SDMMC_INT_RXDR);
        } while (status & SDMMC_INT_RXDR); /*if the RXDR is ready read again*/
        data->bytes_xfered += nbytes;

        if (!remain) {
                if (!sg_miter_next(sg_miter))
                        goto done;
                sg_miter->consumed = 0;
        }
        sg_miter_stop(sg_miter);
        return;

done:
        data->bytes_xfered += nbytes;
        sg_miter_stop(sg_miter);
        host->sg = NULL;
        smp_wmb();
        set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
}

static void dw_mci_write_data_pio(struct dw_mci *host)
{
        struct sg_mapping_iter *sg_miter = &host->sg_miter;
        void *buf;
        unsigned int offset;
        struct mmc_data *data = host->data;
        int shift = host->data_shift;
        u32 status;
        unsigned int nbytes = 0, len;
        unsigned int fifo_depth = host->fifo_depth;
        unsigned int remain, fcnt;

        do {
                if (!sg_miter_next(sg_miter))
                        goto done;

                host->sg = sg_miter->piter.sg;
                buf = sg_miter->addr;
                remain = sg_miter->length;
                offset = 0;

                do {
                        fcnt = ((fifo_depth -
                                 SDMMC_GET_FCNT(mci_readl(host, STATUS)))
                                        << shift) - host->part_buf_count;
                        len = min(remain, fcnt);
                        if (!len)
                                break;
                        host->push_data(host, (void *)(buf + offset), len);
                        offset += len;
                        nbytes += len;
                        remain -= len;
                } while (remain);

                sg_miter->consumed = offset;
                status = mci_readl(host, MINTSTS);
                mci_writel(host, RINTSTS, SDMMC_INT_TXDR);
        } while (status & SDMMC_INT_TXDR); /* if TXDR write again */
        data->bytes_xfered += nbytes;

        if (!remain) {
                if (!sg_miter_next(sg_miter))
                        goto done;
                sg_miter->consumed = 0;
        }
        sg_miter_stop(sg_miter);
        return;

done:
        data->bytes_xfered += nbytes;
        sg_miter_stop(sg_miter);
        host->sg = NULL;
        smp_wmb();
        set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
}

static void dw_mci_cmd_interrupt(struct dw_mci *host, u32 status)
{
        if (!host->cmd_status)
                host->cmd_status = status;

        smp_wmb();

        set_bit(EVENT_CMD_COMPLETE, &host->pending_events);
        tasklet_schedule(&host->tasklet);
}

static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
{
        struct dw_mci *host = dev_id;
        u32 pending;
        unsigned int pass_count = 0;
        int i;

        do {
                pending = mci_readl(host, MINTSTS); /* read-only mask reg */

                /*
                 * DTO fix - version 2.10a and below, and only if internal DMA
                 * is configured.
                 */
                if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO) {
                        if (!pending &&
                            ((mci_readl(host, STATUS) >> 17) & 0x1fff))
                                pending |= SDMMC_INT_DATA_OVER;
                }

                if (!pending)
                        break;

                if (pending & DW_MCI_CMD_ERROR_FLAGS) {
                        mci_writel(host, RINTSTS, DW_MCI_CMD_ERROR_FLAGS);
                        host->cmd_status = pending;
                        smp_wmb();
                        set_bit(EVENT_CMD_COMPLETE, &host->pending_events);
                }

                if (pending & DW_MCI_DATA_ERROR_FLAGS) {
                        /* if there is an error report DATA_ERROR */
                        mci_writel(host, RINTSTS, DW_MCI_DATA_ERROR_FLAGS);
                        host->data_status = pending;
                        smp_wmb();
                        set_bit(EVENT_DATA_ERROR, &host->pending_events);
                        tasklet_schedule(&host->tasklet);
                }

                if (pending & SDMMC_INT_DATA_OVER) {
                        mci_writel(host, RINTSTS, SDMMC_INT_DATA_OVER);
                        if (!host->data_status)
                                host->data_status = pending;
                        smp_wmb();
                        if (host->dir_status == DW_MCI_RECV_STATUS) {
                                if (host->sg != NULL)
                                        dw_mci_read_data_pio(host);
                        }
                        set_bit(EVENT_DATA_COMPLETE, &host->pending_events);
                        tasklet_schedule(&host->tasklet);
                }

                if (pending & SDMMC_INT_RXDR) {
                        mci_writel(host, RINTSTS, SDMMC_INT_RXDR);
                        if (host->dir_status == DW_MCI_RECV_STATUS && host->sg)
                                dw_mci_read_data_pio(host);
                }

                if (pending & SDMMC_INT_TXDR) {
                        mci_writel(host, RINTSTS, SDMMC_INT_TXDR);
                        if (host->dir_status == DW_MCI_SEND_STATUS && host->sg)
                                dw_mci_write_data_pio(host);
                }

                if (pending & SDMMC_INT_CMD_DONE) {
                        mci_writel(host, RINTSTS, SDMMC_INT_CMD_DONE);
                        dw_mci_cmd_interrupt(host, pending);
                }

                if (pending & SDMMC_INT_CD) {
                        mci_writel(host, RINTSTS, SDMMC_INT_CD);
                        queue_work(host->card_workqueue, &host->card_work);
                }

                /* Handle SDIO Interrupts */
                for (i = 0; i < host->num_slots; i++) {
                        struct dw_mci_slot *slot = host->slot[i];
                        if (pending & SDMMC_INT_SDIO(i)) {
                                mci_writel(host, RINTSTS, SDMMC_INT_SDIO(i));
                                mmc_signal_sdio_irq(slot->mmc);
                        }
                }

        } while (pass_count++ < 5);

#ifdef CONFIG_MMC_DW_IDMAC
        /* Handle DMA interrupts */
        pending = mci_readl(host, IDSTS);
        if (pending & (SDMMC_IDMAC_INT_TI | SDMMC_IDMAC_INT_RI)) {
                mci_writel(host, IDSTS, SDMMC_IDMAC_INT_TI | SDMMC_IDMAC_INT_RI);
                mci_writel(host, IDSTS, SDMMC_IDMAC_INT_NI);
                host->dma_ops->complete(host);
        }
#endif

        return IRQ_HANDLED;
}

static void dw_mci_work_routine_card(struct work_struct *work)
{
        struct dw_mci *host = container_of(work, struct dw_mci, card_work);
        int i;

        for (i = 0; i < host->num_slots; i++) {
                struct dw_mci_slot *slot = host->slot[i];
                struct mmc_host *mmc = slot->mmc;
                struct mmc_request *mrq;
                int present;
                u32 ctrl;

                present = dw_mci_get_cd(mmc);
                while (present != slot->last_detect_state) {
                        dev_dbg(&slot->mmc->class_dev, "card %s\n",
                                present ? "inserted" : "removed");

                        /* Power up slot (before spin_lock, may sleep) */
                        if (present != 0 && host->pdata->setpower)
                                host->pdata->setpower(slot->id, mmc->ocr_avail);

                        spin_lock_bh(&host->lock);

                        /* Card change detected */
                        slot->last_detect_state = present;

                        /* Mark card as present if applicable */
                        if (present != 0)
                                set_bit(DW_MMC_CARD_PRESENT, &slot->flags);

                        /* Clean up queue if present */
                        mrq = slot->mrq;
                        if (mrq) {
                                if (mrq == host->mrq) {
                                        host->data = NULL;
                                        host->cmd = NULL;

                                        switch (host->state) {
                                        case STATE_IDLE:
                                                break;
                                        case STATE_SENDING_CMD:
                                                mrq->cmd->error = -ENOMEDIUM;
                                                if (!mrq->data)
                                                        break;
                                                /* fall through */
                                        case STATE_SENDING_DATA:
                                                mrq->data->error = -ENOMEDIUM;
                                                dw_mci_stop_dma(host);
                                                break;
                                        case STATE_DATA_BUSY:
                                        case STATE_DATA_ERROR:
                                                if (mrq->data->error == -EINPROGRESS)
                                                        mrq->data->error = -ENOMEDIUM;
                                                if (!mrq->stop)
                                                        break;
                                                /* fall through */
                                        case STATE_SENDING_STOP:
                                                mrq->stop->error = -ENOMEDIUM;
                                                break;
                                        }

                                        dw_mci_request_end(host, mrq);
                                } else {
                                        list_del(&slot->queue_node);
                                        mrq->cmd->error = -ENOMEDIUM;
                                        if (mrq->data)
                                                mrq->data->error = -ENOMEDIUM;
                                        if (mrq->stop)
                                                mrq->stop->error = -ENOMEDIUM;

                                        spin_unlock(&host->lock);
                                        mmc_request_done(slot->mmc, mrq);
                                        spin_lock(&host->lock);
                                }
                        }

                        /* Power down slot */
                        if (present == 0) {
                                clear_bit(DW_MMC_CARD_PRESENT, &slot->flags);

                                /*
                                 * Clear down the FIFO - doing so generates a
                                 * block interrupt, hence setting the
                                 * scatter-gather pointer to NULL.
                                 */
                                sg_miter_stop(&host->sg_miter);
                                host->sg = NULL;

                                ctrl = mci_readl(host, CTRL);
                                ctrl |= SDMMC_CTRL_FIFO_RESET;
                                mci_writel(host, CTRL, ctrl);

#ifdef CONFIG_MMC_DW_IDMAC
                                ctrl = mci_readl(host, BMOD);
                                /* Software reset of DMA */
                                ctrl |= SDMMC_IDMAC_SWRESET;
                                mci_writel(host, BMOD, ctrl);
#endif

                        }

                        spin_unlock_bh(&host->lock);

                        /* Power down slot (after spin_unlock, may sleep) */
                        if (present == 0 && host->pdata->setpower)
                                host->pdata->setpower(slot->id, 0);

                        present = dw_mci_get_cd(mmc);
                }

                mmc_detect_change(slot->mmc,
                        msecs_to_jiffies(host->pdata->detect_delay_ms));
        }
}

#ifdef CONFIG_OF
/* given a slot id, find out the device node representing that slot */
static struct device_node *dw_mci_of_find_slot_node(struct device *dev, u8 slot)
{
        struct device_node *np;
        const __be32 *addr;
        int len;

        if (!dev || !dev->of_node)
                return NULL;

        for_each_child_of_node(dev->of_node, np) {
                addr = of_get_property(np, "reg", &len);
                if (!addr || (len < sizeof(int)))
                        continue;
                if (be32_to_cpup(addr) == slot)
                        return np;
        }
        return NULL;
}

static struct dw_mci_of_slot_quirks {
        char *quirk;
        int id;
} of_slot_quirks[] = {
        {
                .quirk  = "disable-wp",
                .id     = DW_MCI_SLOT_QUIRK_NO_WRITE_PROTECT,
        },
};

static int dw_mci_of_get_slot_quirks(struct device *dev, u8 slot)
{
        struct device_node *np = dw_mci_of_find_slot_node(dev, slot);
        int quirks = 0;
        int idx;

        /* get quirks */
        for (idx = 0; idx < ARRAY_SIZE(of_slot_quirks); idx++)
                if (of_get_property(np, of_slot_quirks[idx].quirk, NULL))
                        quirks |= of_slot_quirks[idx].id;

        return quirks;
}

/* find out bus-width for a given slot */
static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot)
{
        struct device_node *np = dw_mci_of_find_slot_node(dev, slot);
        u32 bus_wd = 1;

        if (!np)
                return 1;

        if (of_property_read_u32(np, "bus-width", &bus_wd))
                dev_err(dev, "bus-width property not found, assuming width"
                               " as 1\n");
        return bus_wd;
}

/* find the write protect gpio for a given slot; or -1 if none specified */
static int dw_mci_of_get_wp_gpio(struct device *dev, u8 slot)
{
        struct device_node *np = dw_mci_of_find_slot_node(dev, slot);
        int gpio;

        if (!np)
                return -EINVAL;

        gpio = of_get_named_gpio(np, "wp-gpios", 0);

        /* Having a missing entry is valid; return silently */
        if (!gpio_is_valid(gpio))
                return -EINVAL;

        if (devm_gpio_request(dev, gpio, "dw-mci-wp")) {
                dev_warn(dev, "gpio [%d] request failed\n", gpio);
                return -EINVAL;
        }

        return gpio;
}
#else /* CONFIG_OF */
static int dw_mci_of_get_slot_quirks(struct device *dev, u8 slot)
{
        return 0;
}
static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot)
{
        return 1;
}
static struct device_node *dw_mci_of_find_slot_node(struct device *dev, u8 slot)
{
        return NULL;
}
static int dw_mci_of_get_wp_gpio(struct device *dev, u8 slot)
{
        return -EINVAL;
}
#endif /* CONFIG_OF */

static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
{
        struct mmc_host *mmc;
        struct dw_mci_slot *slot;
        const struct dw_mci_drv_data *drv_data = host->drv_data;
        int ctrl_id, ret;
        u8 bus_width;

        mmc = mmc_alloc_host(sizeof(struct dw_mci_slot), host->dev);
        if (!mmc)
                return -ENOMEM;

        slot = mmc_priv(mmc);
        slot->id = id;
        slot->mmc = mmc;
        slot->host = host;
        host->slot[id] = slot;

        slot->quirks = dw_mci_of_get_slot_quirks(host->dev, slot->id);

        mmc->ops = &dw_mci_ops;
        mmc->f_min = DIV_ROUND_UP(host->bus_hz, 510);
        mmc->f_max = host->bus_hz;

        if (host->pdata->get_ocr)
                mmc->ocr_avail = host->pdata->get_ocr(id);
        else
                mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;

        /*
         * Start with slot power disabled, it will be enabled when a card
         * is detected.
         */
        if (host->pdata->setpower)
                host->pdata->setpower(id, 0);

        if (host->pdata->caps)
                mmc->caps = host->pdata->caps;

        if (host->pdata->pm_caps)
                mmc->pm_caps = host->pdata->pm_caps;

        if (host->dev->of_node) {
                ctrl_id = of_alias_get_id(host->dev->of_node, "mshc");
                if (ctrl_id < 0)
                        ctrl_id = 0;
        } else {
                ctrl_id = to_platform_device(host->dev)->id;
        }
        if (drv_data && drv_data->caps)
                mmc->caps |= drv_data->caps[ctrl_id];

        if (host->pdata->caps2)
                mmc->caps2 = host->pdata->caps2;

        if (host->pdata->get_bus_wd)
                bus_width = host->pdata->get_bus_wd(slot->id);
        else if (host->dev->of_node)
                bus_width = dw_mci_of_get_bus_wd(host->dev, slot->id);
        else
                bus_width = 1;

        if (drv_data && drv_data->setup_bus) {
                struct device_node *slot_np;
                slot_np = dw_mci_of_find_slot_node(host->dev, slot->id);
                ret = drv_data->setup_bus(host, slot_np, bus_width);
                if (ret)
                        goto err_setup_bus;
        }

        switch (bus_width) {
        case 8:
                mmc->caps |= MMC_CAP_8_BIT_DATA;
        case 4:
                mmc->caps |= MMC_CAP_4_BIT_DATA;
        }

        if (host->pdata->quirks & DW_MCI_QUIRK_HIGHSPEED)
                mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;

        if (host->pdata->blk_settings) {
                mmc->max_segs = host->pdata->blk_settings->max_segs;
                mmc->max_blk_size = host->pdata->blk_settings->max_blk_size;
                mmc->max_blk_count = host->pdata->blk_settings->max_blk_count;
                mmc->max_req_size = host->pdata->blk_settings->max_req_size;
                mmc->max_seg_size = host->pdata->blk_settings->max_seg_size;
        } else {
                /* Useful defaults if platform data is unset. */
#ifdef CONFIG_MMC_DW_IDMAC
                mmc->max_segs = host->ring_size;
                mmc->max_blk_size = 65536;
                mmc->max_blk_count = host->ring_size;
                mmc->max_seg_size = 0x1000;
                mmc->max_req_size = mmc->max_seg_size * mmc->max_blk_count;
#else
                mmc->max_segs = 64;
                mmc->max_blk_size = 65536; /* BLKSIZ is 16 bits */
                mmc->max_blk_count = 512;
                mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
                mmc->max_seg_size = mmc->max_req_size;
#endif /* CONFIG_MMC_DW_IDMAC */
        }

        host->vmmc = devm_regulator_get(mmc_dev(mmc), "vmmc");
        if (IS_ERR(host->vmmc)) {
                pr_info("%s: no vmmc regulator found\n", mmc_hostname(mmc));
                host->vmmc = NULL;
        } else
                regulator_enable(host->vmmc);

        if (dw_mci_get_cd(mmc))
                set_bit(DW_MMC_CARD_PRESENT, &slot->flags);
        else
                clear_bit(DW_MMC_CARD_PRESENT, &slot->flags);

        slot->wp_gpio = dw_mci_of_get_wp_gpio(host->dev, slot->id);

        mmc_add_host(mmc);

#if defined(CONFIG_DEBUG_FS)
        dw_mci_init_debugfs(slot);
#endif

        /* Card initially undetected */
        slot->last_detect_state = 0;

        /*
         * Card may have been plugged in prior to boot so we
         * need to run the detect tasklet
         */
        queue_work(host->card_workqueue, &host->card_work);

        return 0;

err_setup_bus:
        mmc_free_host(mmc);
        return -EINVAL;
}

static void dw_mci_cleanup_slot(struct dw_mci_slot *slot, unsigned int id)
{
        /* Shutdown detect IRQ */
        if (slot->host->pdata->exit)
                slot->host->pdata->exit(id);

        /* Debugfs stuff is cleaned up by mmc core */
        mmc_remove_host(slot->mmc);
        slot->host->slot[id] = NULL;
        mmc_free_host(slot->mmc);
}

static void dw_mci_init_dma(struct dw_mci *host)
{
        /* Alloc memory for sg translation */
        host->sg_cpu = dmam_alloc_coherent(host->dev, PAGE_SIZE,
                                          &host->sg_dma, GFP_KERNEL);
        if (!host->sg_cpu) {
                dev_err(host->dev, "%s: could not alloc DMA memory\n",
                        __func__);
                goto no_dma;
        }

        /* Determine which DMA interface to use */
#ifdef CONFIG_MMC_DW_IDMAC
        host->dma_ops = &dw_mci_idmac_ops;
        dev_info(host->dev, "Using internal DMA controller.\n");
#endif

        if (!host->dma_ops)
                goto no_dma;

        if (host->dma_ops->init && host->dma_ops->start &&
            host->dma_ops->stop && host->dma_ops->cleanup) {
                if (host->dma_ops->init(host)) {
                        dev_err(host->dev, "%s: Unable to initialize "
                                "DMA Controller.\n", __func__);
                        goto no_dma;
                }
        } else {
                dev_err(host->dev, "DMA initialization not found.\n");
                goto no_dma;
        }

        host->use_dma = 1;
        return;

no_dma:
        dev_info(host->dev, "Using PIO mode.\n");
        host->use_dma = 0;
        return;
}

static bool mci_wait_reset(struct device *dev, struct dw_mci *host)
{
        unsigned long timeout = jiffies + msecs_to_jiffies(500);
        unsigned int ctrl;

        mci_writel(host, CTRL, (SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET |
                                SDMMC_CTRL_DMA_RESET));

        /* wait till resets clear */
        do {
                ctrl = mci_readl(host, CTRL);
                if (!(ctrl & (SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET |
                              SDMMC_CTRL_DMA_RESET)))
                        return true;
        } while (time_before(jiffies, timeout));

        dev_err(dev, "Timeout resetting block (ctrl %#x)\n", ctrl);

        return false;
}

#ifdef CONFIG_OF
static struct dw_mci_of_quirks {
        char *quirk;
        int id;
} of_quirks[] = {
        {
                .quirk  = "supports-highspeed",
                .id     = DW_MCI_QUIRK_HIGHSPEED,
        }, {
                .quirk  = "broken-cd",
                .id     = DW_MCI_QUIRK_BROKEN_CARD_DETECTION,
        },
};

static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
{
        struct dw_mci_board *pdata;
        struct device *dev = host->dev;
        struct device_node *np = dev->of_node;
        const struct dw_mci_drv_data *drv_data = host->drv_data;
        int idx, ret;

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata) {
                dev_err(dev, "could not allocate memory for pdata\n");
                return ERR_PTR(-ENOMEM);
        }

        /* find out number of slots supported */
        if (of_property_read_u32(dev->of_node, "num-slots",
                                &pdata->num_slots)) {
                dev_info(dev, "num-slots property not found, "
                                "assuming 1 slot is available\n");
                pdata->num_slots = 1;
        }

        /* get quirks */
        for (idx = 0; idx < ARRAY_SIZE(of_quirks); idx++)
                if (of_get_property(np, of_quirks[idx].quirk, NULL))
                        pdata->quirks |= of_quirks[idx].id;

        if (of_property_read_u32(np, "fifo-depth", &pdata->fifo_depth))
                dev_info(dev, "fifo-depth property not found, using "
                                "value of FIFOTH register as default\n");

        of_property_read_u32(np, "card-detect-delay", &pdata->detect_delay_ms);

        if (drv_data && drv_data->parse_dt) {
                ret = drv_data->parse_dt(host);
                if (ret)
                        return ERR_PTR(ret);
        }

        if (of_find_property(np, "keep-power-in-suspend", NULL))
                pdata->pm_caps |= MMC_PM_KEEP_POWER;

        if (of_find_property(np, "enable-sdio-wakeup", NULL))
                pdata->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;

        return pdata;
}

#else /* CONFIG_OF */
static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
{
        return ERR_PTR(-EINVAL);
}
#endif /* CONFIG_OF */

int dw_mci_probe(struct dw_mci *host)
{
        const struct dw_mci_drv_data *drv_data = host->drv_data;
        int width, i, ret = 0;
        u32 fifo_size;
        int init_slots = 0;

        if (!host->pdata) {
                host->pdata = dw_mci_parse_dt(host);
                if (IS_ERR(host->pdata)) {
                        dev_err(host->dev, "platform data not available\n");
                        return -EINVAL;
                }
        }

        if (!host->pdata->select_slot && host->pdata->num_slots > 1) {
                dev_err(host->dev,
                        "Platform data must supply select_slot function\n");
                return -ENODEV;
        }

        host->biu_clk = devm_clk_get(host->dev, "biu");
        if (IS_ERR(host->biu_clk)) {
                dev_dbg(host->dev, "biu clock not available\n");
        } else {
                ret = clk_prepare_enable(host->biu_clk);
                if (ret) {
                        dev_err(host->dev, "failed to enable biu clock\n");
                        return ret;
                }
        }

        host->ciu_clk = devm_clk_get(host->dev, "ciu");
        if (IS_ERR(host->ciu_clk)) {
                dev_dbg(host->dev, "ciu clock not available\n");
        } else {
                ret = clk_prepare_enable(host->ciu_clk);
                if (ret) {
                        dev_err(host->dev, "failed to enable ciu clock\n");
                        goto err_clk_biu;
                }
        }

        if (IS_ERR(host->ciu_clk))
                host->bus_hz = host->pdata->bus_hz;
        else
                host->bus_hz = clk_get_rate(host->ciu_clk);

        if (drv_data && drv_data->setup_clock) {
                ret = drv_data->setup_clock(host);
                if (ret) {
                        dev_err(host->dev,
                                "implementation specific clock setup failed\n");
                        goto err_clk_ciu;
                }
        }

        if (!host->bus_hz) {
                dev_err(host->dev,
                        "Platform data must supply bus speed\n");
                ret = -ENODEV;
                goto err_clk_ciu;
        }

        host->quirks = host->pdata->quirks;

        spin_lock_init(&host->lock);
        INIT_LIST_HEAD(&host->queue);

        /*
         * Get the host data width - this assumes that HCON has been set with
         * the correct values.
         */
        i = (mci_readl(host, HCON) >> 7) & 0x7;
        if (!i) {
                host->push_data = dw_mci_push_data16;
                host->pull_data = dw_mci_pull_data16;
                width = 16;
                host->data_shift = 1;
        } else if (i == 2) {
                host->push_data = dw_mci_push_data64;
                host->pull_data = dw_mci_pull_data64;
                width = 64;
                host->data_shift = 3;
        } else {
                /* Check for a reserved value, and warn if it is */
                WARN((i != 1),
                     "HCON reports a reserved host data width!\n"
                     "Defaulting to 32-bit access.\n");
                host->push_data = dw_mci_push_data32;
                host->pull_data = dw_mci_pull_data32;
                width = 32;
                host->data_shift = 2;
        }

        /* Reset all blocks */
        if (!mci_wait_reset(host->dev, host))
                return -ENODEV;

        host->dma_ops = host->pdata->dma_ops;
        dw_mci_init_dma(host);

        /* Clear the interrupts for the host controller */
        mci_writel(host, RINTSTS, 0xFFFFFFFF);
        mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */

        /* Put in max timeout */
        mci_writel(host, TMOUT, 0xFFFFFFFF);

        /*
         * FIFO threshold settings  RxMark  = fifo_size / 2 - 1,
         *                          Tx Mark = fifo_size / 2 DMA Size = 8
         */
        if (!host->pdata->fifo_depth) {
                /*
                 * Power-on value of RX_WMark is FIFO_DEPTH-1, but this may
                 * have been overwritten by the bootloader, just like we're
                 * about to do, so if you know the value for your hardware, you
                 * should put it in the platform data.
                 */
                fifo_size = mci_readl(host, FIFOTH);
                fifo_size = 1 + ((fifo_size >> 16) & 0xfff);
        } else {
                fifo_size = host->pdata->fifo_depth;
        }
        host->fifo_depth = fifo_size;
        host->fifoth_val = ((0x2 << 28) | ((fifo_size/2 - 1) << 16) |
                        ((fifo_size/2) << 0));
        mci_writel(host, FIFOTH, host->fifoth_val);

        /* disable clock to CIU */
        mci_writel(host, CLKENA, 0);
        mci_writel(host, CLKSRC, 0);

        tasklet_init(&host->tasklet, dw_mci_tasklet_func, (unsigned long)host);
        host->card_workqueue = alloc_workqueue("dw-mci-card",
                        WQ_MEM_RECLAIM | WQ_NON_REENTRANT, 1);
        if (!host->card_workqueue)
                goto err_dmaunmap;
        INIT_WORK(&host->card_work, dw_mci_work_routine_card);
        ret = devm_request_irq(host->dev, host->irq, dw_mci_interrupt,
                               host->irq_flags, "dw-mci", host);
        if (ret)
                goto err_workqueue;

        if (host->pdata->num_slots)
                host->num_slots = host->pdata->num_slots;
        else
                host->num_slots = ((mci_readl(host, HCON) >> 1) & 0x1F) + 1;

        /*
         * Enable interrupts for command done, data over, data empty, card det,
         * receive ready and error such as transmit, receive timeout, crc error
         */
        mci_writel(host, RINTSTS, 0xFFFFFFFF);
        mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
                   SDMMC_INT_TXDR | SDMMC_INT_RXDR |
                   DW_MCI_ERROR_FLAGS | SDMMC_INT_CD);
        mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE); /* Enable mci interrupt */

        dev_info(host->dev, "DW MMC controller at irq %d, "
                 "%d bit host data width, "
                 "%u deep fifo\n",
                 host->irq, width, fifo_size);

        /* We need at least one slot to succeed */
        for (i = 0; i < host->num_slots; i++) {
                ret = dw_mci_init_slot(host, i);
                if (ret)
                        dev_dbg(host->dev, "slot %d init failed\n", i);
                else
                        init_slots++;
        }

        if (init_slots) {
                dev_info(host->dev, "%d slots initialized\n", init_slots);
        } else {
                dev_dbg(host->dev, "attempted to initialize %d slots, "
                                        "but failed on all\n", host->num_slots);
                goto err_workqueue;
        }

        /*
         * In 2.40a spec, Data offset is changed.
         * Need to check the version-id and set data-offset for DATA register.
         */
        host->verid = SDMMC_GET_VERID(mci_readl(host, VERID));
        dev_info(host->dev, "Version ID is %04x\n", host->verid);

        if (host->verid < DW_MMC_240A)
                host->data_offset = DATA_OFFSET;
        else
                host->data_offset = DATA_240A_OFFSET;

        if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO)
                dev_info(host->dev, "Internal DMAC interrupt fix enabled.\n");

        return 0;

err_workqueue:
        destroy_workqueue(host->card_workqueue);

err_dmaunmap:
        if (host->use_dma && host->dma_ops->exit)
                host->dma_ops->exit(host);

        if (host->vmmc)
                regulator_disable(host->vmmc);

err_clk_ciu:
        if (!IS_ERR(host->ciu_clk))
                clk_disable_unprepare(host->ciu_clk);

err_clk_biu:
        if (!IS_ERR(host->biu_clk))
                clk_disable_unprepare(host->biu_clk);

        return ret;
}
EXPORT_SYMBOL(dw_mci_probe);

void dw_mci_remove(struct dw_mci *host)
{
        int i;

        mci_writel(host, RINTSTS, 0xFFFFFFFF);
        mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */

        for (i = 0; i < host->num_slots; i++) {
                dev_dbg(host->dev, "remove slot %d\n", i);
                if (host->slot[i])
                        dw_mci_cleanup_slot(host->slot[i], i);
        }

        /* disable clock to CIU */
        mci_writel(host, CLKENA, 0);
        mci_writel(host, CLKSRC, 0);

        destroy_workqueue(host->card_workqueue);

        if (host->use_dma && host->dma_ops->exit)
                host->dma_ops->exit(host);

        if (host->vmmc)
                regulator_disable(host->vmmc);

        if (!IS_ERR(host->ciu_clk))
                clk_disable_unprepare(host->ciu_clk);

        if (!IS_ERR(host->biu_clk))
                clk_disable_unprepare(host->biu_clk);
}
EXPORT_SYMBOL(dw_mci_remove);



#ifdef CONFIG_PM_SLEEP
/*
 * TODO: we should probably disable the clock to the card in the suspend path.
 */
int dw_mci_suspend(struct dw_mci *host)
{
        int i, ret = 0;

        for (i = 0; i < host->num_slots; i++) {
                struct dw_mci_slot *slot = host->slot[i];
                if (!slot)
                        continue;
                ret = mmc_suspend_host(slot->mmc);
                if (ret < 0) {
                        while (--i >= 0) {
                                slot = host->slot[i];
                                if (slot)
                                        mmc_resume_host(host->slot[i]->mmc);
                        }
                        return ret;
                }
        }

        if (host->vmmc)
                regulator_disable(host->vmmc);

        return 0;
}
EXPORT_SYMBOL(dw_mci_suspend);

int dw_mci_resume(struct dw_mci *host)
{
        int i, ret;

        if (host->vmmc)
                regulator_enable(host->vmmc);

        if (!mci_wait_reset(host->dev, host)) {
                ret = -ENODEV;
                return ret;
        }

        if (host->use_dma && host->dma_ops->init)
                host->dma_ops->init(host);

        /* Restore the old value at FIFOTH register */
        mci_writel(host, FIFOTH, host->fifoth_val);

        mci_writel(host, RINTSTS, 0xFFFFFFFF);
        mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
                   SDMMC_INT_TXDR | SDMMC_INT_RXDR |
                   DW_MCI_ERROR_FLAGS | SDMMC_INT_CD);
        mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);

        for (i = 0; i < host->num_slots; i++) {
                struct dw_mci_slot *slot = host->slot[i];
                if (!slot)
                        continue;
                if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) {
                        dw_mci_set_ios(slot->mmc, &slot->mmc->ios);
                        dw_mci_setup_bus(slot, true);
                }

                ret = mmc_resume_host(host->slot[i]->mmc);
                if (ret < 0)
                        return ret;
        }
        return 0;
}
EXPORT_SYMBOL(dw_mci_resume);
#endif /* CONFIG_PM_SLEEP */

static int __init dw_mci_init(void)
{
        printk(KERN_INFO "Synopsys Designware Multimedia Card Interface Driver");
        return 0;
}

static void __exit dw_mci_exit(void)
{
}

module_init(dw_mci_init);
module_exit(dw_mci_exit);

MODULE_DESCRIPTION("DW Multimedia Card Interface driver");
MODULE_AUTHOR("NXP Semiconductor VietNam");
MODULE_AUTHOR("Imagination Technologies Ltd");
MODULE_LICENSE("GPL v2");